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Last Friday, 20 May 2016, was a historic day at the Princeton Plasma Physics Laboratory (PPPL). It was a day that the $94-million upgrade to National Spherical Torus Experiment (NSTX-U), which took almost four years to build, was officially launched by the U.S. Department of Energy (DOE) Secretary Ernest Moniz.

Funded by the DOE Office of Science, NSTX-U addresses how to create fusion, the process that powers the Sun, on Earth, in a device based on the spherical tokamak concept.

It’s the fourth state of matter: Solid, liquid, gas, and plasma. Plasma is a super-heated gas, so hot that its electrons get out of the atom’s orbit and roam free. A gas thus becomes a plasma when extreme heat causes its atoms to shed their electrons.

It’s everywhere. Plasma is the most abundant form of visible matter in the universe – it is thought to make up 99 percent of what we see in the night sky. Plasma populates and dominates the vast regions of interstellar and interplanetary space.

Stars, like the sun, are gigantic balls of plasma. And there are billions of them, so studying plasma can help us understand the cosmos.

At the JET reactor at Culham Centre for Fusion Energy, the film maker Tom Scott talks to the engineers about fusion power, being the hottest place in the solar system, deliberate disruptions, and about the surround-sound speakers that give a diagnostic test you might not expect.

Harnessing the energy produced in nuclear fusion reactions is an ongoing grand challenge. Recent Nature Physics Insight focuses on the achievements made so far and the trials ahead, highlighting that at the core of nuclear fusion lies some fascinating physics.

The quest for Fusion Energy has been approached through decades in different manners. Most of the contributions are done by the governmental sector, National Laboratories and Universities given that its duration is expected to be long and therefore not so well suited for normal investors.

This scenario has recently started to change with the Venture Capital, where investors are free to speculate in high-risk and high-compensation projects, as explained by BBC Future its recent article.

Using an advanced plasma global code called XGCa, researchers at the Princeton Plasma Physics Laboratory (PPPL) have confronted the conventional view of the so-called bootstrap current with results clarifying the origin of the current at the tokamak edge.